To get the latest Flash for Ubuntu - simply install Chrome Web Browser
If you don't want to spend much time configuring your Ubuntu and need the latest Flash plugin all you need to do is to point your browser (Firefox?) to this address https://www.google.fi/chrome/browser/desktop/ and install Chrome Web Browser.
Chrome has Flash pre-installed inside and you never need to take care of Flash updates again. Chrome does it for you. Only keep using Chrome.